Tetsuwan Atom (1980) - episode 41 - 22 Sep, 1981

One evening, Astro is watching a story on TV about a boy who finds a bottle that contains a genie, who is released and promptly threatens to eat the boy. The boy instead asks to see if the genie can drink all the water in the sea; the genie grants his wish and drinks so much water that he explodes. As the story ends, a large meteor falls into a mountain valley some distance away. Dr. Elefun, Astro, and a team of scientists head off to investigate the crash. At the impact site, Astro uncovers a large metallic meteor-like object that turns out to be a mass of metal parts. Astro constructs the parts, and finds that they form a giant robot. A message capsule hidden in the mass calls the robot "Garon", which came from an alien planet and apparently has terraforming abilities. That night, a thunderstorm erupts, and Garon is brought to life by a stray bolt of lightning, frightening the scientists. Astro subdues Garon before he can cause damage, trapping him back in the impact site and buried in molten lava. However, one of the scientists, Dr. Adams, later uncovers Garon and secretly smuggles him to a remote island in the South Pacific. There, he requests Garon terraform the island to resemble the planet of his origin. As Garon proceeds to terraform the island, he also alters the atmosphere around the island to that of his planet. The scientists discover that his atmosphere has almost no oxygen content, but all perish before they can escape. The tradewinds begin carrying the poisonous atmosphere across the South Pacific, killing all life in its way. Astro is sent by Elefun to investigate, and he encounters Garon, still busily terraforming the island. Realizing that he can't win by brute force alone, he tricks Garon into also altering the gravity of the island to match that of his planet for at least one minute. Garon falls for his trick, and after altering the gravity of the island, gets shot back out into outer space, creating a vacuum around the island that pulls all of the poisonous gas along with him. (Source: Wikipedia)